This contractor will be the Coordinating Center for the collaborative clinical trial, PostCABG (Coronary Artery Bypass Graft) Study. The primary objective of this project is to determine if lowering serum cholesterol by drug treatment or by lifestyle modification (dietary exercise, and cessation of smoking) will have a beneficial effect on the rate of longterm (after 1 year) graft reocclusion. PostCABG will be a randomized clinical trial which will also have a biobehavioral component and an epidemiologic study component. The objective of the biobehavioral study component is to identify the biobehavioral and psychosocial factors that contribute to the successful adjustment after CABG. The objective of the epidemiologic study component is to identify clinical, biochemical and hemostatic factors that correlate with native coronary atherosclerosis and graft occlusion. Subsidiary objectives of the trial include assessing the effects of interventions on (1) progression of coronary atherosclerosis in the native vessels and internal mammary grafts; (2) ventricular function; (3) morbidity; and (4) quality of life. Specifically, the Coordinating Center will have as its major responsibilities participation in the design of the trial during Phase I, and collecting, editing, storing, and analyzing data generated by the clinical centers during Phase II. It will provide a detailed report of accumulating data and clinical centers performance at sixmonth intervals for the Data and Safety Monitoring Board during Phase II. The Coordinating Center will be supported for two years beyond termination of patient followup to complete analysis of study data and assist in preparation of scientific reports for publication and presentation (Phase III).